The TAIEX, the weighted index on the Taiwan Stock Exchange, closed at 21,092.75 points Wednesday, plummeting by 999.46 points from the previous day, marking the third steepest single-day drop in its history.

Meanwhile, overseas institutional investors sold a net 100.75 billion new Taiwan dollars (about 3.13 billion U.S. dollars) in shares, setting a new record for the highest single-day sell-off.

Among the major weighted stocks in the TAIEX, Taiwan Semiconductor Manufacturing Company (TSMC) dropped by 51 dollars, a decline of 5.43 percent, to close at 889 dollars, falling below the critical 900-dollar mark.

Hon Hai Precision Industry Co. fell by 2.97 percent to 179.5 dollars, while smartphone IC designer MediaTek Inc. saw a significant decline of 6.97 percent, closing at 1,135 dollars.

The three largest single-day drops in TAIEX history have all occurred in the third quarter of this year.